Single year contract, with an option for another year.
I'd be surprised if he hasn't announced his retirement by the end of season fly-aways.
Oh.. In that case you could be right. Unless he wants to have a look at what the 2022 regs may bring Aston Martin? (Although they may need to wait until 2023 to be more competitive as they'll need to get a good luck at the 2022 Merc first... )